Many dispenser systems are known in the prior art for dispensing paper toweling from rolls thereof. In some cases, the paper toweling is comprised of individual paper towel segments separated by perforated tear lines, and in others the toweling has no perforated tear lines formed therein, severing or cutting individual sheets from the toweling accomplished by some suitable severing structure incorporated in the dispenser.
Many paper towel dispensing cabinets employ motor driven toweling support rollers or drums to transport toweling during the dispensing operation. Rotation of the rollers is accomplished in a variety of ways, including mechanical switching associated with the roller or by employing electronic methods to control motor “on” time and control roller rotation. Such arrangements include both dispensers which are manually actuated, as by means of a push button, and those employing a sensor, such as a sensor sensing proximity of a user's hand, to initiate operation.
U.S. Pat. No. 6,820,785, issued Nov. 23, 2004, discloses an electro-mechanical roll towel dispenser including a housing with a roll carrier disposed therein to rotatably support a roll of towel material. An electro-mechanical feed mechanism is disposed in the housing to dispense measured sheets of the towel material. The feed mechanism operates in a first mechanical operational mode wherein the towel sheets are dispensed by a user grasping and pulling on a tail of the towel material extending from the housing and a second electrical operational mode wherein a measured length of a next sheet is automatically fed from the housing to define the tail for the next user.
The dispenser of U.S. Pat. No. 6,820,785 includes a sensor for detecting a parameter that is changed by an initial pull exerted on a tail of a web of material extending from the opening of the dispenser. The sensor also generates a signal sent from the sensor to a control circuit or circuitry causing the motor employed in the apparatus to drive the feed mechanism until a measured length of web material that includes the tail of web material has been fed from the dispenser in the form of a measured sheet for subsequent removal by the user.
Similar devices are disclosed in U.S. Pat. No. 3,730,409 and Patent Publication Document WO 00/63100. The devices of these latter two documents have sensors for detecting movement of a tail end of web material such that the feed mechanism is activated in response to detecting the movement.
It is known to use magnets and a sensor (Hall effect sensors or reed switches) to control rotation of a roller or drum to control the amount of dispensed toweling. By placing a magnet in a specific location on the roller, and a magnet sensor nearby, it is possible to count the revolutions of the roller. The drawbacks of this method include relatively high manufacturing expense, since magnets and sensors are expensive. Also, multiple magnets are required when one revolution of the roller does not provide sufficient control of the dispensed material.
Another traditional method is to use timers to control the length of time the motor driving the roller is energized. The primary drawback of this approach is that it requires significant and ongoing calibration due to variability of power source to the motor and variability in the mechanical structure (“friction” is variable).
The following documents are also believed to be representative of the current state of the prior art in this field: U.S. Pat. No. 3,715,085, issued Feb. 6, 1973, U.S. Pat. No. 3,730,409, issued May 1, 1973, U.S. Pat. No. 3,737,087, issued Jun. 5, 1973, U.S. Pat. No. 3,949,918, issued Apr. 13, 1976, U.S. Pat. No. 3,998,308, issued Dec. 21, 1976, U.S. Pat. No. 4,666,099, issued May 19, 1987, U.S. Pat. No. 4,676,131, issued Jun. 30, 1987, U.S. Pat. No. 4,721,265, issued Jan. 26, 1988, U.S. Pat. No. 4,738,176, issued Apr. 19, 1988, U.S. Pat. No. 4,790,490, issued Dec. 13, 1988, U.S. Pat. No. 4,796,825, issued January 1989, U.S. Pat. No. 4,960,248, issued Oct. 2, 1990, U.S. Pat. No. 5,131,302, issued Jul. 21, 1992, U.S. Pat. No. 5,452,832, issued Sep. 26, 1995, U.S. Pat. No. 5,772,291, issued Jun. 30, 1998, U.S. Pat. No. 6,079,305, issued Jun. 27, 2000, U.S. Pat. No. 6,105,898, issued Aug. 22, 2000, U.S. Pat. No. 6,412,655, issued Jul. 2, 2002, U.S. Pat. No. 6,412,679, issued Jul. 2, 2002, Patent Document No. WO 9959457, dated November 1999, Patent Document No. WO 0063100, dated October 2000, U.S. Pat. No. 7,398,944, issued Jul. 15, 2008, U.S. Pat. No. 6,892,620, issued May 17, 2005, U.S. Pat. No. 7,044,421, issued May 16, 2006, U.S. Pat. No. 4,573,750, issued Mar. 4, 1986, U.S. Pat. No. 4,826,262, issued May 2, 1989, U.S. Pat. No. 6,446,901, issued Sep. 10, 2002, U.S. Pat. No. 4,270,818, issued Jun. 2, 1981, U.S. Pat. No. 6,112,631, issued Sep. 5, 2000, U.S. Pat. No. 5,375,920, issued Dec. 27, 1994, U.S. Pat. No. 7,354,015, issued Apr. 8, 2008, U.S. Pat. No. 4,738,176, issued Apr. 19, 1988, U.S. Pat. No. 4,790,490, issued Dec. 13, 1988, U.S. Pat. No. 6,079,305, issued Jun. 27, 2000, U.S. Pat. No. 6,419,136, issued Jul. 16, 2002, U.S. Pat. No. 6,412,679, issued Jul. 2, 2002, U.S. Pat. No. 5,441,189, issued Aug. 15, 1995, U.S. Pat. No. 5,878,381, issued Mar. 2, 1999, U.S. Pat. No. 5,691,919, issued Nov. 25, 1997, U.S. Pat. No. 5,452,832, issued Sep. 26, 1995, U.S. Pat. No. 5,340,045, issued Aug. 23, 1994, U.S. Pat. No. 5,335,811, issued Aug. 9, 1994, U.S. Pat. No. 5,244,263, issued Sep. 14, 1993, U.S. Pat. No. 4,848,854, issued Jul. 18, 1989, U.S. Pat. No. 4,738,176, issued Apr. 19, 1988, U.S. Pat. No. 4,270,818, issued Jun. 2, 1981, U.S. Pat. No. 4,170,390, issued Oct. 9, 1979, U.S. Pat. No. 5,657,945, issued Aug. 19, 1997, U.S. Pat. No. 4,122,738, issued Oct. 31, 1978, U.S. Pat. No. 6,012,664, issued Jan. 11, 2000, U.S. Pat. No. 5,816,514, issued Oct. 6, 1998, U.S. Pat. No. 5,417,783, issued May 23, 1995, U.S. Pat. No. 4,717,043, issued Jan. 5, 1988, U.S. Pat. No. 5,630,526, issued May 20, 1997, U.S. Pat. No. 6,363,824, issued Apr. 2, 2002, U.S. Pat. No. 6,293,486, issued Sep. 25, 2001, U.S. Pat. No. 6,695,246, issued Feb. 24, 2004, U.S. Pat. No. 6,854,684, issued Feb. 15, 2005, U.S. Pat. No. 6,988,689, issued Jan. 24, 2006, U.S. Pat. No. 7,325,767, issued Feb. 5, 2008, U.S. Pat. No. 7,325,768, issued Feb. 5, 2008, U.S. Pat. No. 7,168,602, issued Jan. 30, 2007, U.S. Pat. No. 6,592,067, issued Jul. 15, 2003, U.S. Pat. No. 7,341,170, issued Mar. 11, 2008, U.S. Pat. No. 7,182,288, issued Feb. 27, 2007, U.S. Pat. No. 7,296,765, issued Nov. 20, 2007, U.S. Pat. No. 6,977,588 issued Dec. 20, 2005 and U.S. Pat. No. 6,820,785, issued Nov. 23, 2004.
As will be seen below, the system of the present invention utilizes the unique approach of employing targets on a paper toweling support roller sensed by capacitance sensor structure during rotation of the roller, the capacitance sensor structure sensing capacitance changes caused by the rotating targets. Use of the approach of this invention allows control of paper length, prevents of motor jams and turns the motor control on and off based on capacitance sensing.
A search of the prior art relating to employment of capacitance sensing techniques, including in systems utilizing rotating drums located the following patent documents: U.S. Pat. No. 6,036,137, issued Mar. 14, 2000, U.S. Pat. No. 5,692,313, issued Dec. 2, 1997, U.S. Patent Application Pub. No. US 2007/0099189, pub. May 3, 2007, U.S. Patent Application Pub. No. US 2007/0079526, pub. Apr. 12, 2007, Foreign Patent documents: JP 2003-187410, KR 10-2005-021832, DE 101 31 019, EP 096 178, U.S. Pat. No. 6,047,894, issued Apr. 11, 2000, U.S. Pat. No. 4,448,196, issued May 15, 1984, U.S. Pat. No. 7,256,957, issued Aug. 14, 2007, U.S. Pat. No. 6,439,068, issued Aug. 27, 2002, U.S. Patent Pub. No. US 2008/0309380, pub. Dec. 18, 2008, U.S. Pat. No. 6,119,523, issued Sep. 19, 2000, U.S. Pat. No. 5,351,685, issued Oct. 4, 1994, U.S. Pat. No. 7,301,350, issued Nov. 27, 2007.
The systems disclosed in the located prior art do not remotely relate to paper towel dispensers. There is no teaching or suggestion of the unique combinations of structural components or method steps disclosed and claimed herein.